1. Field of the Invention
This invention relates to pyrido[3,2,1-jk]carbazol derivatives represented by the formula (I) hereinafter defined and the pharmaceutically acceptable salts thereof which are useful as antimicrobial, anti-cancer and antiviral agents, a process for preparing the same and a pharmaceutical composition containing pyrido[3,2,1-jk]carbazol derivative.
2. Description of the Prior Art
It is known that certain types of polyheterocyclic compounds exhibit antimicrobial activities. For example, Gerster et al U.S. Pat. No. 3,917,609 discloses substituted derivatives of 1,2-dihydro-6-oxo-6H-pyrrolo[3,2,1-ij]quinoline which are useful as antimicrobial agents or as intermediates for the preparation of antimicrobial agents.
Also, Gerster et al U.S. Pat. Nos. 3,896,131; 3,985,882; 3,969,463; 4,001,243 and 4,014,877 disclose 6,7-dihydro-1-oxo-1H, 5H-benzo[ij]quinolizine derivatives having antimicrobial activities.
However, the pyrido[3,2,1-jk]carbazol derivatives of the present invention are structurally different from these quinoline and quinolizine compounds.